Use GnuPG 2 for backup/restore

ipa-backup and ipa-restore now use GnuPG 2 for asymmetric encryption, too.
The gpg2 command behaves a bit different and requires a gpg2 compatible
config directory. Therefore the --keyring option has been deprecated.

The backup and restore tools now use root's GPG keyring by default.
Custom configuration and keyring can be used by setting GNUPGHOME
environment variables.

Fixes: https://pagure.io/freeipa/issue/7560
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

ipaplatform/base/paths.py

@@ -167,8 +167,8 @@ class BasePathNamespace(object):
     CHROMIUM_BROWSER = "/usr/bin/chromium-browser"
     FIREFOX = "/usr/bin/firefox"
     GETCERT = "/usr/bin/getcert"
-    GPG = "/usr/bin/gpg"
     GPG2 = "/usr/bin/gpg2"
+    GPG_CONNECT_AGENT = "/usr/bin/gpg-connect-agent"
     GPG_AGENT = "/usr/bin/gpg-agent"
     IPA_GETCERT = "/usr/bin/ipa-getcert"
     KADMIN_LOCAL = '/usr/sbin/kadmin.local'